clang/test/SemaCXX/cxx2b-consteval-if.cpp

   1 // RUN: %clang_cc1 -std=c++23 -verify %s
   2
   3 namespace PR52206 {
   4 constexpr auto f() {
   5   if consteval  { return 0;   }
   6   if !consteval { return 0.0; } // expected-error {{'auto' in return type deduced as 'double' here but deduced as 'int' in earlier return statement}}
   7 }
   8
   9 constexpr auto g() {
  10   if !consteval { return 0;   }
  11   if consteval  { return 0.0; } // expected-error {{'auto' in return type deduced as 'double' here but deduced as 'int' in earlier return statement}}
  12 }
  13
  14 constexpr auto h() {
  15   if consteval  { return 0; }
  16   if !consteval { return 0; } // okay
  17 }
  18
  19 constexpr auto i() {
  20   if consteval {
  21     if consteval { // expected-warning {{consteval if is always true in an immediate context}}
  22       return 1;
  23     }
  24     return 2;
  25   } else {
  26     return 1.0; // expected-error {{'auto' in return type deduced as 'double' here but deduced as 'int' in earlier return statement}}
  27   }
  28 }
  29
  30 void test() {
  31   auto x1 = f();
  32   constexpr auto y1 = f();
  33
  34   auto x2 = g();
  35   constexpr auto y2 = g();
  36
  37   auto x3 = h();
  38   constexpr auto y3 = h();
  39
  40   auto x4 = i();
  41   constexpr auto y4 = i();
  42 }
  43 } // namespace PR52206
  44
  45 consteval int *make() { return new int; }
  46 auto f() {
  47   if constexpr (false) {
  48     if consteval {
  49       // Immediate function context, so call to `make()` is valid.
  50       // Discarded statement context, so `return 0;` is valid too.
  51       delete make();
  52       return 0;
  53     }
  54   }
  55   return 0.0;
  56 }